Address for mailings question

Have a customer getting mailings picked up by their spam filter since the display address is the one we specified, the address the mailing actually comes from is an @e2ma.net, which they don't want to whitelist entirely. We've updated our spf record, but unless it's coming from the display email we chose it doesn't look like they're going to receive it. Is there any way to have the mailing address match the displayed mail address?

I just heard back from Delivery and I am told there's no way to do this. Our sending infrastructure is, by necessity, restricted to only send using our domain. They next best step, since they can't whitelist all of the info, is to whitelist something like this: